Post-streptococcal glomerulonephritis (PSGN) is a very infrequent complication of infection with the bacteria known as group A streptococcus. Group A strep most frequently infects either the pharynx where it causes strep throat, or the skin where it causes a local infection know as cellulitis. Rarely, after a patient has experienced a strep infection, deposits of immune system proteins and remaining parts of the strep bacterial cell walls form complexes and can build up in the kidneys. As the very small structures in the kidney responsible for filtering blood become exposed to the complexes, they become inflamed and can begin to lose normal function. The resulting leakage and destruction of red blood cells through these damaged kidney structures results in the most common presenting symptom of PSGN: a dark colored urine containing destroyed blood cells. Other symptoms include high blood pressure and fluid buildup called edema that occurs as a result of decreased normal kidney architecture.

In general, treatment for PSGN is to provide symptomatic relief until the body can heal the damaging immune complexes. The hypertension and fluid accumulation is usually treated with a diuretic which increases urine output. Activity should be restricted for a few days after the diagnosis is made.

In children, PSGN has an excellent prognosis with the vast majority of cases resolving within a few weeks. In adults, however, particularly those with preexisting heart or kidney disease, the condition can be much more serious with a defined mortality rate.